Method and apparatus for making corrugated building sheets



Jan. 14, 1969 v. G. FRANC 3,421,353 METHOD AND APPARATUS FOR MAKINGCORRUGATED BUILDING SHEETS Original Filed Dec. 15, 1964 Sheet. of 2 Fig.I

8 r FF r r r'" 22 I 4p 23 23' 23' 23 U E17 5 0o 00 90 ea 00 o Fm Ee% 0%"4 L3 L4 L8 L5L6 7 Fig. 2

Jan. 14, 1969 v, FRANC 3,421,353

METHOD AND APPARATUS FOR MAKING CORRUGATED BUILDING SHEETSOriginalF'iled Dec. 15, 1964 Sheet 2 of 2 A M;- *M F2 3 x I A 3g MQ k\A\}\3BZ 4, 44 77 7 73 77% fi 23, WW 4 k 1' 4 43 ms 54 4 54 Q71 1 2 1 V;5 I 237 Vz I: 77] i nwavrae VICTOP G. FPA/VC AL? A Q ATTORNEY UnitedStates Patent 3,421,353 METHOD AND APPARATUS FOR MAKING CORRUGATEDBUILDING SHEETS Victor G. Franc, Wireton, Pa., assiguor to H. H.Robertson Company, Pittsburgh, Pa., a corporation of PennsylvaniaOriginal application Dec. 15, 1964, Ser. No. 418,426. Di-

vided and this application Oct. 12, 1967, Ser. No. 683,059

US. Cl. 72-181 Int. Cl. B21d /08; B21b 1/24 5 Claims ABSTRACT OF THEDISCLOSURE Cross-references to related applications This is a divisionof application Ser. No. 418,426, filed Dec. 15, 1964, now abandoned, andassigned to the assignee of the present invention.

This invention concerns an improved corrugated building sheet and amethod for making the same.

The corrugated building sheets with which this invention is concernedare those which have a plurality of relatively fiat crests andalternating flat valleys parallel with the crests and having essentiallyflat sloping webs diverging from the crests to the adjacent valleys.Such corrugated building sheets are shown, for example, in US. Patents1,982,243, 1,936,228, 2,696,281, 2,789,530. Heretofore such corrugatedsheets have been available in lengths up to about 12 feet. While warpingtendencies were manifested in these prior corrugated building sheets,the adverse effects of those warping tendencies could be overcomebecause of the relatively short lengths of such sheets.

More recently corrugated building sheets have become available in longerlengths. Sheets of feet, feet, and even feet length are commerciallyavailable today. Warping tendencies in these long sheets are irregularand difficult to overcome. Dissimilar warping of successive corrugatedbuilding sheets make it difficult to nest such sheets together forminimum volume packaging. Side-byside and end-to-end overlapping ofwarped building sheets is difiicult, and the resulting building wall isfrequently unattractive.

The warping tendency in corrugated sheets may arise from a variety ofmetallurgical reasons, for example, coldrolled metal sheets usually arethicker in the center than at the edges, a phenomenon known in the metalindustry as high crown metal. The crown of the metal sheet may beprecisely centered or may range for some distance over both sides of thesheet center. However even metal sheets with no detectable crown presentwarping tendencies upon corrugation. Metal sheets with nonuniformities,hardness differential temper variations, temperature differentials andinequalities resulting from aging phenomena have been advanced asreasons for warping tendencies in corrugated building sheets.

Without regard to the origin of the warping tendencies, the presentinvention provides a method and apparatus for making corrugated buildingsheets which are substantially free of warping manifestations.

According to the present invention, a pair of the sloping webs of thecorrugated building sheet, one web on each side of the center of thesheet, are initially prepared as substantially flat sloping webs similarto all of the other sloping webs of the corrugated sheet. After thosetwo selected ones of the sloping webs have been formed, and before anyof the laterally displaced sloping webs are formed, the two selectedones of the sloping webs are passed between a set of forming rolls tomodify the configuration of the two selected sloping webs from asubstantially fiat configuration, as formed, to an arcuateconfiguration. Thereafter the corrugated building sheet is completedaccording to prior art practices by forming the laterally displacedcrests, valleys and sloping webs as required. The resulting corrugatedbuilding sheets are essentially free of any manifestations of warpingtendencies even in lengths of 40 feet.

The invention will be more fully illustrated and described in thefollowing detailed description by reference to the accompanying drawingsin which:

FIGURE 1 is a perspective view of the corrugated building sheet of thisinvention;

FIGURE 2 is a side elevation view of milling apparatus adapted to rollform the present building sheets; and

FIGURES 3, 4, 5, 6, 7 and 8 are fragmentary crosssection views takenalong the lines 3-3, 4-4, 5-5, 66, 77 and 88 respectively of FIGURE 2.

Referring to FIGURE 1 there is illustrated a corrugated building sheet10 having a plurality of crests 11 and alternating valleys 12 which areconnected by substantially fiat sloping webs 13. Such corrugatedbuilding sheets normally terminate with fragmentary sloping webs 14along each edge. The term crests and the term valleys are relative sincefrequently these flat surfaces are identical in dimensions, differingonly in which set of surfaces (the crests) is closer to the viewer thanthe other set (the valleys). By reversal of a corrugated sheet, hence,the surfaces become interchanged. The corrugated sheet 10 has foursurfaces 11 which have been designated crests and has five surfaces 12which have been designated valleys. Clearly, if the corrugated sheet 10were turned over, the five surfaces 12 could be accurately designatedcrests and the four surfaces 11 could be accurately designated valleys.

A typical metal building sheet has crests 11 and valleys 12 1.625 incheswide and separated by 3.5 inches centerto-center. The plane of thecrests is 1.5 inches apart from the plane of the valleys. The over-allwidth of the building sheet is about 31 inches. Such building sheet has4 crests and 5 valleys, as shown in FIGURE 1. The sloping webs 13 forman angle 44 to 45 with the plane of the crests.

According to this invention, two of the sloping webs 13a, 13b arechanged from a substantially flat configuration as formed, to an arcuateconfiguration in such manner that the arcuate configuration is virtuallyundetectable visually as a departure from the substantially flatconfiguration of the remaining ones of the sloping webs 13. The arcuatesloping webs 13a, 13b are formed into the corrugated building sheetduring its fabrication after the sloping webs 13a, 131) have been fullyformed in a substantially flat configuration and prior to the formationof any succeeding laterally displaced sloping webs 13.

Process FIGURE 2 presents a side elevation view of a roll forming linefor the assembly of the present corrugated building sheets. A coil 20 ofmetal sheet 21 is fed to a cutting means 22. Cut-to-length sheets 23 arepassed sequentially through rolling stands 3, 4, 8, 5, 6 and 7 to formthe present corrugated building sheets 23 which are nested together in ashipping stack 24 after formation. Each of the rolling stands 3, 4, 5,6, 7 is commonplace in the corrugated building sheet rolling industry.Cross-sections through these metal stands are presented in the drawingsFIGURES 3, 4, 5, 6 and 7. Throughout the drawings 3, 4, 5, 6, 7 the toprolls are designated by the letter A and the bottom rolls by the letterB. Each of the rolls in any stand is designated further by sequentialsubscripts from left to right.

As shown in FIGURE 3, the metal sheet 23 passes between rolls 3A (above)and rolls 3B and 3B (below). As a result the metal sheet 23 has formedtherein a center crest C and two flat sloping webs W and W In thatcondition the sheet 23 passes to the station 4, where, as shown inFIGURE 4, the sheet passes beneath rollers 4A 4A and 4A and aboverollers 4B and 4B The roll 4A serves principally to align the sheet 23whereas the rollers 4A and 413 cooperate to form the valley V and thesloping web W Likewise the rollers 4A and 4B cooperate to form thevalley V and web W Additional crests, valleys and sloping webs areintroduced into the metal sheet 23 in stations 5, 6 and 7. It will beobserved that, in station 7 (FIGURE 7), the rollers 7A and 7B form acrest C and a fragmentary sloping web W Similarly the rollers 7A and 7Bform the crest C and the fragmentary sloping web W A corrugated buildingsheet formed by passage through stations 3, 4, 5, 6 and 7 would conformwith prior art practices and would be susceptible to severe warpage,especially in long lengths. The additional forming step of thisinvention is illustrated in FIGURE 8 wherein a pair of forming rolls 8Aand 8A is attached to an upper shaft while a pair of corresponding rolls8B and 8B is attached to a bottom shaft. The rolls 8A and 8A have aconvex configuration whereas the rolls 8B and 8B have a concaveconfiguration. As the metal sheet 23 enters the nip of the rolling stand8, it has the configuration seen in FIGURE 4, i.e., it contains a crestC two valleys V and V and four substantially flat sloping webs W W W andW The rolls in rolling station 8 perform Work on the sloping webs W andW by changing the form from a substantially flat sheet to an arcuatesurface identified in FIGURE 8 as SW and SW It will be observed that thelateral portions of the metal sheet 23 (displaced from the arcuatesloping ribs SW and SW are essentially unaltered from the initial flatcondition, i.e., the lateral portions have experienced no corrugatingstresses.

It should further be observed that the sloping webs W and W have beencompletely formed as substantially flat surfaces prior to the conversionof those surfaces to an arcuate configuration SW and SW as shown inFIGURE 8.

It should further be observed that the two arcuate surfaces SW and SWare disposed equidistant from the center crest C i.e., there is one ofthe arcuate sloping surfaces on each lateral half of the finishedcorrugated building sheet. In the event extremely wide corrugatedbuilding sheets are manufactured, it may be desirable to provide morethan two of the arcuate sloping surfaces in the sheet. The two arcuatesurfaces SW and SW illustrated in FIGURE 8 correspond to the arcuatewebs 13a and 13b of the finished building sheet as shown in FIG- URE 1.In FIGURE 8, the sloping surfaces SW and SW laterally adjoin the centralvalleys V and V Further, those two sloping surfaces SW and SW are formedfrom initially substantially flat sloping webs W and W which wereconverging, i.e., which were nonparallel.

I claim:

1. In rolling mill apparatus for fabricating from a fiat sheet of metala corrugated building sheet having plural fiat crests and alternatingplural flat valleys parallel with the said crests, and havingessentially flat sloping webs diverging from each of the said valleys tothe adjacent ones of the said crests, said apparatus including a rollingmachine, means for advancing a said fiat sheet of metal to and throughsaid rolling machine, said rolling machine having sequential rollerformers for forming first a central one of the said crests with thelaterally adjacent webs; thence for forming the laterally adjacentvalleys and their laterally adjacent webs; thence for forming thelaterally adjacent crests and their laterally adjacent webs; thencesufficient additional roller formers to complete the said corrugatedbuilding sheet; the improvement in said rolling mill apparatuscomprising:

a pair of convex roller formers and a pair of opposed concave rollerformers positioned in said rolling machine sequentially after the rollerformers which provide the central ones of the said plural valleys andprior to the last ones of the roller formers in the said rollingmachine,

said convex and concave roller formers being adapted to alter at leastone of the already-formed webs from a flat configuration to a curvedconfiguration, whereby the resulting corrugated building sheet issubstantially free of warpage.

2. In a fabricating process for making from a fiat sheet of metal acorrugated building sheet having plural flat crests and alternatingplural flat valleys parallel with the said crests and having essentiallyflat sloping webs diverging from each of the said valleys to theadjacent ones of the said crests, the said process including sequentialrolling said sheet of metal through roller formers for sequentiallyforming a central crest and its adjacent webs; thence the laterallyadjacent valleys and their laterally adjacent webs; thence the nextlaterally adjacent crests and their laterally adjacent webs and so forthuntil the entire corrugated sheet is formed, the improvement in the saidprocess comprising:

after the said central crest and its laterally adjacent valleys havebeen formed and before the outside webs have been formed, altering thesurface configuration of at least one of the already formed webs from aflat-surface to a curved surface and thereafter completing the formingof the said building sheet without altering the said curved surface ofthe said already-formed web, whereby the resulting corrugated buildingsheet is substantially free of warpage.

3. The process of claim 2 wherein the said sheet of metal has a nominalthickness of 20 to 26 gauge and has an organic coating applied to atleast one surface thereof.

4. The process of claim 2 wherein the said corrugated building sheet hasfour valleys and five crests and wherein the said already-formed websare those laterally adjacent to the two interior valleys.

5. The process of claim 2 wherein the said flat-surface of the saidalready-formed webs is curved to present a concave surface when viewedfrom that side of the said sheet nearest the said valleys.

References Cited UNITED STATES PATENTS 1,485,917 3/1924 Harter 72l81 X1,900,722. 3/1933 Manske et a1. 72l80 X 2,708,958 5/1955 Crafton 72-181X 3,051,214 8/1962 Rutten 72181 MILTON S. MEHR, Primary Examiner.

U.S. Cl. X.R. 72366

